Metal and metal alloy powders have many important applications, especially in electronics and dental industries. Metal and metal alloy particles are widely used in conductor compositions for hybrid integrated circuits, multilayer ceramic capacitors, actuators and other uses.
There are many methods currently used to manufacture metal powders. These include chemical reduction methods, physical processes such as atomization or milling, thermal decomposition, and electrochemical processes. These processes tend to be very hard to control and give irregular shaped particles that are agglomerated. In addition, these processes are either unable to make alloy particles that contain greater than two elements or the particle sizes are very large and the alloy ratios are very hard to control.
The aerosol decomposition process involves the conversion of a precursor solution to a powder. (See U.S. Pat. No. 6,338,809, which is incorporated herein by reference.) This process involves the generation of droplets, transport of the droplets with a gas into a heated reactor, the removal of the solvent by evaporation, the decomposition of the salt to form a porous solid particle, and then the densification of the particle to give fully dense, spherical particles. Conditions are such that there is no interaction of droplet-to-droplet or particle-to-particle and there is no chemical interaction of the droplets or particles with the carrier gas.